FIG. 3 shows a perspective view of a lid portion of a prior art semiconductor device before the electrode of the device is bent.
In FIG. 3, the reference numeral 1 designates a lid portion constructed by plastic forming. The reference numeral 2 designates a recessed portion provided on the lid portion 1 so as to enable insertion of a nut. The reference numeral 3 designates an electrode which is inserted into the lid portion 1 during plastic molding. The reference numeral 4 designates a center line of the electrode 3. The reference numeral 5 designates a supposed line showing a position to which the center line 4 is to come when no distortion arises in the electrode bending process. The reference numeral 6 designates a supposed line showing a position to which the center line 4 is supposed to come when some distortion arises in the electrode bending process. The reference numeral A designates a line showing a direction along which the electrode is bent. FIG. 4 is a perspective view showing the same lid portion as that of FIG. 3, but this FIG. 4 illustrates a state after the electrode bending process.
The bending process of the electrode will be described.
Nuts (not shown) are inserted into the recessed portions 2 of the lid portion 1 in a state shown in FIG. 3. Thereafter bending of the electrodes 3 is conducted and the arrangement shown in FIG. 4 is obtained. When the electrode 3 is accurately bent with no deviations during the bending process, the center line 4 is aligned with the line 5. In this case, the center of the nut inserted into the recessed portion 2 is situated on the supposed line 5, whereby no difficulty will arise in the insertion of a screw. However, when the center line 4 is aligned on one of the lines 6 due to some deviation (such as an improper force application during the electrode bending process), the center of the nut is not situated on the supposed line 6. Difficulty will then arise in the insertion of a screw as well as tremendously worsening the external appearance. The longer the length X of the electrode 3, the more likely such deviations are to arise and such deviations are likely to have a greater positional deviation. Furthermore, when such deviations arise, the position of the curved electrode 3 must be modified. In order to avoid such problems, the electrode bending process must be conducted quite precisely.
The prior art semiconductor device is constructed in such a manner, and the electrode is likely to be distorted and curved due to some deviations during the bending process. This causes an obstruction to screw insertion and detracts from the external appearance. This also requires considerable precision during the electrode bending process.